Method for estimating castor seed weight from fruit weight considering the variance of the conversion factor.

This method can be employed to estimate the castor seed weight from the castor fruit weight considering that the conversion factor has an intrinsic variance that should be accounted for in the analysis of variance. This method consists in the correction of the Total Sum of Squares when the seed weight is calculated from the fruit weight using a conversion factor and the data is subjected to Analysis of Variance. Conversion factors were measured in 1,000 samples, and the variance of the data was calculated and validated on a diversity of genotypes and experimental conditions.•Adopting a conversion factor for estimating castor seed weight reduces the labor required for running experiments.•When castor seed weight is estimated from the fruit weight, the variance of the conversion factor should be accounted for in the Analysis of Variance.•The conversion factor and its variance may be influenced by genotypes, experimental treatments, and environmental conditions.